The present invention relates to a semiconductor module.
Semiconductor memories are used in various information-processing equipment such as large computers, personal computers, portable equipment, etc. and have been yearly increased in necessary capacity. In keeping with an increase in capacity, semiconductor memories are increased in mount area, which constitutes a factor that hinders miniaturization of the equipment. Hereupon, techniques have been developed for high-density mounting of semiconductor memories. As a technique for mounting many packages on a mount substrate having a limited area, techniques, in which a plurality of packages are stacked and mounted on a mount substrate, have been developed. Constructions, in which semiconductor modules are stacked with paste therebetween, are disclosed in JP-A-2002-176135, JP-A-8-236694, and JP-A-2000-286380.
In the case where a high-density mounted module is to be formed, however, semiconductor modules are reduced in outer dimension, or mounted in high-density. Therefore, when semiconductor packages are mounted on a mount substrate, or on other semiconductor packages, modules are preferably formed to be thin as a whole. In the case where packages are thin, however, they are small in flexural rigidity, so that warp is generated at the time of package assembling and there is a need of restricting generation of disadvantages in subsequent mount processes and at the time of inspection.
Also, it is desired that a mounted package with a semiconductor element mounted thereon be constructed to be excellent in ability of heat radiation while ensuring reliability in a mounted portion. The invention solves at least one of these problems.